This invention relates to roof vents.
It has heretofore been known that it is desirable to provide roof vents for ventilating a roof.
Prior roof vents have been known. For example, U.S. Pat. No. 4,924,761 discloses a roof vent comprising a onepiece plastic body having a base wall with transversely spaced rows of integral vanes extending from one surface. The vanes of adjacent rows define a sinuous path through which air is vented when the vent is positioned with the vanes engaging the roof and the base wall spaced from the roof. The vanes also prevent water and snow from entering beneath the vent.
The roof vent of U.S. Pat. No. 5,009,149 discloses a similar roof vent constructed to further inhibit water or snow from entering underneath the roof vent. The vanes of the inner row have a longer length than the vanes of the outer row and are provided with an axially extending straight portions having a curved portion to further deflect moisture.
A roof vent for a hip roof is disclosed in assigned U.S. Pat. No. 5,174,076, issued Dec. 29, 1992, having a common assignee with the present application. A separate wall with a longitudinally extending portion is provided with a roof vent where the wall lies between the ends of the vanes of the roof vent and the roof and the longitudinally extending portion extends toward the base wall of the roof vent. This separate wall prevents snow and water from entering laterally underneath the roof vent.
In co-pending application Ser. No. 08/010,609 filed Jan. 28, 1993, having a common assignee with the present invention, there is disclosed a roof vent comprising an integral one-piece plastic body including a base wall with air guiding vanes to ventilate the interior of a building. A plurality of spaced intermediate supports are provided along the central longitudinal axis of the plastics body. The intermediate supports are adapted to facilitate folding at the center of the vent and maintain a straight line bend and to provide support for the central portion of the vent. Thus, the vent is prevented from bowing or collapsing due to the weight from snow buildup or due to the impact of nailing the vent to the roof. Additionally, the supports overlap for use with roofs having different angles.
In each of the above described roof vents a strip of porous material is provided to prevent insects and blowing snow from entering the building while permitting air to exit from under the roof. It has been found that the placement of the strip of porous material is critical.
Among the objectives of the present invention are to provide a plastic roof vent wherein the strip of material is positioned accurately and carefully; wherein the strip is fixed in position; and to provide a method and apparatus for inserting and bonding the liner material to the plastic roof vent.
In accordance with the invention, a longitudinally extending thinner portion is provided adjacent the vanes and is bonded as by heat bonding or ultrasonic welding to the roof vent. In accordance with the method and apparatus, the plastic roof vent is bent along the thinner hinge line to provide access for placing of the strip of porous material and for bonding the strip to the plastic roof vent.